Crusher gauges have been known in the art for many years. Some earlier examples include a copper pellet crusher using a piston arrangement as depicted in U.S. Pat. No. 2,620,652 by Hartmann (1952). A later disclosure, U.S. Pat. No. 2,870,631 by Musser et al (1959) depicts a device for positioning and housing of crusher gauges. In more recent years, it has been desired to measure peak pressures inside large caliber artillery shells. In order to accomplish these measurements, cylindrically-shaped crusher gauges have been used. As these crusher gauges must remain oriented and positioned within a shell during the firing of the shell, gauge holders within the shell are necessary. Typical of such prior art gauge holder is the neoprene holder device having a neoprene locking ring. The neoprene holder has a series of bore holders around the periphery for insertion of the crusher gauges. Additionally, a center bore is provided for the purpose of mounting the holder by sliding it over the shell's primer tube. The locking ring is also center-bored and is slid down over the primer tube in a similar manner. As the locking ring's outside diameter is slightly greater than the inside diameter of the edges of the peripheral holes on the holder, the locking ring wedges against the crusher gauges holding them in place.
Certain problems remain with these prior art holders. Typically, these gauge holders are inserted into the neoprene disk that is placed over the primer tube at the bottom of the cartridge case. Another neoprene disk, the locking ring, is placed over the gauge holder assembly. When the propelling charge with the gauge holder assembly is rammed to its seated position, the assembly slides forward on the primer tube as the propellant bed shifts forward (leaving a finite space). During ignition, the gauge assembly is forced into the base of the case damaging the gauges. During this process gauges may be dislodged from the holder and upon extraction and ejection of the spent case the gauges fall into the gun operating mechanism, foul the gun barrel, are propelled through the barrel forward of the gun mount or remain in the cartridge case. When the gauge holder is slammed into the base of the cartridge case the steel/copper holder is deformed and could be affecting the copper gauge readings.